A few months ago I asked how I could change the config so that blocks destroyed by spells won't be re-created after a few seconds. The command I was given was:
/mconfig spell override parameters.bypass_undo true

It worked perfectly back then, but now after I type "/magic load" to load the new configuration, my spells cannot destroy any blocks and all I get is "Something went wrong" in the chat.

"Something went wrong" means there are errors. Please go check your server logs.

Probably the plugin isn't loading, or some errors is happening. If you've updated MythicMobs but not Magic then that's probably it.

Were you able to figure this out?

Unfortunately no, but it seems World Guard is also creating errors and not working correctly, so it may not be a problem with the addon. I might try it again without WG and with different versions to see if it works. I guess I can play without destroying blocks, as I don't play that much nowadays. Thanks for the help.

It sounds a bit like something got messed up in Magic's configs, probably nothing to do with the WG errors.

If you want to just reset everything, you could try delete all the files in plugins/Magic, but make sure to backup /plugins/Magic/data and put it back after deleting the configs.